(a) Field of the Invention
The invention relates to an artificial occlusion device designed for the endovascular treatment of aneurysms, such as intracranial, or for closing any body lumen, such as vascular lumen or other. The invention also relates to the use of the occlusion device and a method for treating an aneurysm.
(b) Description of Prior Art
Direct surgical clipping has been used for the treatment of most intracranial aneurysms. However, surgical difficulties and related morbidity with certain aneurysms have stimulated the development of endovascular procedures. Despite the favorable results of endovascular platinum coil treatment in acutely ruptured aneurysms, neck remnants and recurrences are frequent and may compromise the long term success of this treatment modality (Jean Raymond et al., Neurosurgery, 41:6, 1997). This mechanical failure of the device of the prior art is not surprising and coils alone without efficient healing mechanisms may not be strong enough to counteract the continuous repetitive force of the abnormal flow which often remains following incomplete endovascular treatment.
The mechanism of surgical clipping directly apposes the vessel wall, leading to rapid xe2x80x9cprimary healingxe2x80x9d. By opposition, following endovascular treatment, the wound margins are separated by coils and healing depends on fibrous replacement of clot between coils and growth of a neointima at the coilxe2x80x94parent vessel interface. There is a general pattern of wound healing in the vessel wall, which occurs following a wide variety of traumatic or pathological conditions. These mechanisms are also involved in repairing experimental aneurysms. In vivo studies suggest that healing of experimental aneurysms involves coagulation, inflammation, cellular migration, proliferation, matrix secretion with the formation of a neointima at the neck of treated aneurysms. The proposed invention is designed to increase neointima formation at the neck of treated lesions in order to improve long-term results of endovascular treatment.
Intracranial aneurysms can be treated by four different principles:
1) Surgical clipping permits closure of the aneurysmal neck from the outside, with close apposition of the edges of the xe2x80x9cwoundxe2x80x9d and satisfactory healing, but necessitates craniotomy and dissection at the base of the brain.
2) Parent vessel occlusion consisting of occlusion of the vessel along with the aneurysm or with the intent to decrease blood flow to the aneurysm, is possible only in certain anatomical sites, and in the presence of an adequate collateral circulation.
3) Parent vessel stenting is a new possibility but is currently technically feasible only in proximal vessels or in extracranial aneurysms such as the aorta (WO 98/12990 and WO 93/08767).
4) Selective endosaccular occlusion of the aneurysm is currently the most frequently used method of endovascular treatment. This method can be performed with three (3) different types of material:
a) Liquid or fluid agents which polymerize inside the aneurysm or immediately before exiting the catheter; this strategy has never been routinely used because of the fear of cerebral embolization;
b) Detachable balloons have been introduced by Serbinenko, Romodanov and Scheghlov and have more frequently been used between 1978 to 1990. The expertise necessary for using these devices was difficult to master; these devices led to a high incidence of inadvertent aneurysm rupture and were also plagued with a high incidence of recurrences; and
c) Microcoils; these metallic devices became popular with the Guglielmi Detachable Coil system, which permitted to reposition the coil and detach it only when it was felt to be in a satisfactory position. The availability of this system has greatly increased the use of the endovascular route in the treatment of intracranial aneurysms. This device is much safer to use than detachable balloons, free coils, or polymeric embolic agents. The main advantage of soft coils compared to detachable balloons is the fact that they will conform to the shape of the aneurysm. However, even in aneurysms which can be sufficiently occluded in order to prevent rebleeding of the aneurysm during the acute phase, recurrences after a few months areand frequent and this fear of recurrences is currently the major drawback of the technique and the most important argument against a more widespread clinical application.
It would be highly desirable to be provided with a device for treating aneurysms, which could stimulate neointima formation at the neck of treated aneurysms for improving long-term results of endovascular treatment.
It would also be highly desirable to be provided with a method for treating aneurysms, which could increase neointima formation at the neck of treated aneurysms for improving long-term results of endovascular treatment.
One aim of the present invention is to provide a device for treating aneurysms, which could stimulate neointima formation at the neck of treated aneurysms for improving long-term results of endovascular treatment.
Another aim of the present invention is to provide a method for treating aneurysms, which could increase neointima formation at the neck of treated aneurysms for improving long-term results of endovascular treatment.
In accordance with the present invention there is provided a device for treating aneurysms, which could stimulate neointima formation at the neck of treated aneurysms for improving long-term results of endovascular treatment.
In accordance with the present invention there is provided a method for treating aneurysms, which could increase neointima formation at the neck of treated aneurysms by emission of radiation.
Still in accordance with the present invention there is provided an occlusion device for treating an aneurysm, comprising a detachable filling element and at least one radioactive source, said detachable filling element and said radioactive source being adapted to be inserted into a vessel at least in close proximity of a neck of an aneurysm, said radioactive source stimulating neointima formation for obstructing the neck of the aneurysm or filling up the aneurysm.
The detachable filling element may be a coil, preferably a platinum coil.
The radioisotope source is preferably a xcex2-emitting source. The radioisotope source may be made of a polymer and a radioisotope. The xcex2-emitting source is preferably at least one xcex2-emitting source from Antimony-124, Cesium-134, Cesium-137, Calcium-45, Calcium-47, Cerium 141, Chlorine-36, Cobalt-60, Europium-152, Gold-198, Hafnium-181, Iodine-131, Iridium-192, Iron-59, Lutetium-177, Mercury-203, Neodymium-147, Nickel-63, Phosphorus-32, Phosphorus-33, Rhenium-186, Rubidium-86, Ruthenium-106, Samarium-153, Scandium-46, Silver-110m, Strontium-89, Strontium-90, Sulfur-35, Technetium-99, Terbium-160, Thulium-170, and Yttrium-90.
In accordance with another aspect of the invention, the occlusion device may further comprise a second filling element selected from the group consisting of a coil, a polymer, a bioactive peptide, an aqueous solution, and a gel. The aqueous solution is preferably a polymerizable solution capable of polymerization once in the aneurysm.
Further in accordance with the present invention, there is provided the use of an occlusion device as defined above for the treatment of an aneurysm.
Also in accordance with the present invention, there is provided a kit for the treatment of an aneurysm. The kit comprises:
a detachable filling element adapted to be inserted into a vessel at least in close proximity with a neck of an aneurysm; and
a radioactive source adapted to be inserted with the detachable filling element;
wherein the radioactive source stimulates neointima formation causing obstruction of the neck of the aneurysm or filling up the aneurysm.
Further in accordance with the present invention, there is provided a method for treating an aneurysm comprising inserting a detachable filling element and a radioactive source into a vessel at least in close proximity of a neck of an aneurysm, the radioactive source stimulating neointima formation causing obstruction of the neck of the aneurysm or filling up the aneurysm.